A New Ischemic Model Using a Radiofrequency Wire Electrode in a Rabbit Hindlimb

Abstract

The purpose of this study was to establish an ischemic rabbit hindlimb model using a radiofrequency (RF) wire electrode. We inserted a polytetrafluoroethylene-coated wire with a 2-cm exposed tip into the left superficial femoral artery of seven New Zealand white rabbits and performed RF ablation (RFA) while pulling the wire back. We assessed the clinical findings, angiography, computed tomography perfusion, and permeability surface until 6 weeks after RFA. The angiography demonstrated complete obstruction from the proximal external iliac artery to the distal superficial femoral artery and showed a gradual increment in the angiogenic score, which represents the degree of angiogenesis (r = 0.86, p < 0.0001). The left-to-right ratios of the computed tomography perfusion and permeability surface were significantly reduced after 4 days (p < 0.05), and then they gradually increased with time. We conclude that endovascular RFA using an RF wire electrode is a reproducible and measurable way to create an ischemic rabbit hindlimb model.

Arterial Occlusion Using a Microguidewire as a Radiofrequency Electrode

“…The mechanisms of endovascular arterial ablation using RF-generated heat include in situ thrombus formation and vessel wall desiccation that leads to shrinkage and retraction of the vessel. [4][5][6][7][8]11 The indications for this technique include most diseases and conditions that require embolization. However, interventionists should be aware of heat transfer outside the artery and the possibility of rupturing occluded arteries.…”

“…Caution is advised when the RF energy is delivered near nerve or other important structures. 8 To prevent injury of important adjacent structures, the electric current, power, and duration should be controlled and optimized through further investigation.…”

“…In this procedure, a microguidewire positioned in the targeted vessel delivers radiofrequency (RF) energy to effectively occlude arteries by causing in situ thrombus formation and vessel wall damage. [3][4][5][6][7][8] The site of occlusion can be accurately controlled by positioning the tip of the microguidewire anode. 7 The nontarget embolization that occurs during therapeutic vessel occlusion using embolic materials can be avoided, and the occlusion remains permanent.…”